Structural development and electronic properties of hot filament low pressure chemical vapor deposited fluorocarbon polymer films

2006 ◽  
Vol 21 (1) ◽  
pp. 242-254 ◽  
Author(s):  
A.C. Rastogi ◽  
S.B. Desu
Keyword(s):  
Polymer Films ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Chain Structure ◽  
Leakage Currents ◽  
Filament Temperature ◽  
Pressure Chemical ◽  
Fluorocarbon Polymer ◽  
Hot Filament ◽  
Substrate Temperatures

Fluorocarbon polymer films in the poly(tetrafluoroethylene) (PTFE)-like structure are formed by a low-pressure chemical vapor deposition technique using the hot filament excitation of the gaseous C3F6O precursor. The filament and substrate temperatures were found to influence the structure of the deposited films. Infrared absorption and electron spectroscopy studies reveal that a PTFE-like (CF2)2n linear molecular chain structure evolves by an adsorption driven nucleation and CF2 polymerization process in the films deposited with low (450 °C) filament and high (70 °C) substrate temperatures. The films formed at a low substrate temperature (–165 °C) show a higher concentration of CF and C–CF bond defects and shorter (CF2)2n chains. A high (8–10 at.%) oxygen concentration in the films deposited at 600 °C filament temperature is attributed to the reaction of the (CF2)2n chains with COF and peroxyradicals arising from the dissociation of CF3C(O)F and affects the thermal stability of the films. Such reactions are not involved in the film growth at a low (450 °C) filament temperature. These films have much lower (<2 at.%) bonded oxygen content. The films having an ordered (CF2)2n chain structure formed at 70 °C are characterized by low leakage currents ∼7 × 10−11 A cm−2 at 0.1 MV cm−1 field. In comparison, high leakage currents ∼1 × 10−8 A cm−2 are observed for the films having a higher concentration of C–F and C–CF bonds.

Deposition and Properties of AlN Films Prepared by Low Pressure CVD with a Metalorganic Precursor

1993 ◽  
Vol 335 ◽  
Author(s):  
M. J. Cook ◽  
P. K. Wu ◽  
N. Patibandla ◽  
W. B. Hillig ◽  
J. B. Hudson
Keyword(s):  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Low Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fiber Coating ◽  
Pressure Chemical ◽  
Substrate Temperatures ◽  
Carbon Concentrations

AbstractAluminum nitride films were deposited on Si (100) and sapphire (1102) substrates by low pressure chemical vapor deposition using the metalorganic precursor trisdimethylaluminum amide, [(CH3)2AlNH2]3. Depositions were carried out in a cold wall reactor with substrate temperatures between 500 and 700 °C and precursor temperatures between 50 and 80 °C. The films were analyzed by X-ray photoelectron spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy. The films were generally smooth and adherent with colors ranging from transparent to opaque grey. Cracking and spallation were seen to occur at high film thickness. Deposition rates ranged from 20 to 300 Å/min and increased with both precursor and substrate temperature. Carbon concentrations were small, < 5 at. %, while oxygen concentrations were higher and showed a characteristic profile versus depth in the film. High temperature compatibility testing with sapphire/AlN/MoSi2 samples was carried out to determine film effectiveness as a fiber coating in a composite.

Hot filament assisted diamond growth at low temperatures with oxygen addition

1997 ◽  
Vol 12 (5) ◽  
pp. 1344-1350 ◽  
Author(s):  
Z. Li Tolt ◽  
L. Heatherly ◽  
R. E. Clausing ◽  
C. S. Feigerle
Keyword(s):  
Growth Rate ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Oxygen Effect ◽  
Optimum Conditions ◽  
Filament Temperature ◽  
Oxygen Addition ◽  
Hot Filament ◽  
Substrate Temperatures

Addition of a small amount of oxygen to the CH4 and H2 feed gas permits hot filament assisted chemical vapor deposition (HFCVD) of diamond at significantly lower filament and substrate temperatures. The former can be reduced to as low as 1400 °C and the latter to 450 °C. The amount of oxygen required is much lower than what has been used in most studies of the oxygen effect. For each CH4%, there is a narrow window in the O/C ratio, where diamond can be deposited at low temperature. This window shifts to higher O/C ratios as the CH4% increases and expands with increases in filament temperature. The effect of changing substrate and filament temperatures on growth rate and film quality are often not consistent with previous experiences with HFCVD of diamond. Increasing the filament temperature does not always improve the growth rate and film quality, and the non-diamond carbon content in the film is dramatically reduced at lower substrate temperatures. Optimum conditions were found that gave reasonable growth rates (∼0.5 μm/h) with high film quality at filament temperatures below 1750 °C and substrate temperatures below 600 °C. With these reductions in operating temperatures, power consumption can be significantly reduced and the filament lifetime extended indefinitely.

In Situ Phosphorus-Doped Poly-Si by Low Pressure Chemical Vapor Deposition for Passivating Contacts

2020 ◽  
Author(s):  
Meric Firat ◽  
Hariharsudan Sivaramakrishnan Radhakrishnan ◽  
Maria Recaman Payo ◽  
Filip Duerinckx ◽  
Rajiv Sharma ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Pressure Chemical ◽  
Phosphorus Doped

scholarly journals Unusual Dependence of the Diamond Growth Rate on the Methane Concentration in the Hot Filament Chemical Vapor Deposition Process

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 426
Author(s):  
Byeong-Kwan Song ◽  
Hwan-Young Kim ◽  
Kun-Su Kim ◽  
Jeong-Woo Yang ◽  
Nong-Moon Hwang
Keyword(s):  
Growth Rate ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Methane Concentration ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Lower Growth ◽  
Filament Temperature ◽  
Diamond Phase ◽  
Hot Filament

Although the growth rate of diamond increased with increasing methane concentration at the filament temperature of 2100 °C during a hot filament chemical vapor deposition (HFCVD), it decreased with increasing methane concentration from 1% CH4 –99% H2 to 3% CH4 –97% H2 at 1900 °C. We investigated this unusual dependence of the growth rate on the methane concentration, which might give insight into the growth mechanism of a diamond. One possibility would be that the high methane concentration increases the non-diamond phase, which is then etched faster by atomic hydrogen, resulting in a decrease in the growth rate with increasing methane concentration. At 3% CH4 –97% H2, the graphite was coated on the hot filament both at 1900 °C and 2100 °C. The graphite coating on the filament decreased the number of electrons emitted from the hot filament. The electron emission at 3% CH4 –97% H2 was 13 times less than that at 1% CH4 –99% H2 at the filament temperature of 1900 °C. The lower number of electrons at 3% CH4 –97% H2 was attributed to the formation of the non-diamond phase, which etched faster than diamond, resulting in a lower growth rate.

A Novel Direct Liquid Injection Low Pressure Chemical Vapor Deposition System (DLI-LPCVD) for the Deposition of Thin Films

2017 ◽  
Vol 19 (8) ◽  
pp. 1700193 ◽  
Author(s):  
Mattias Vervaele ◽  
Bert De Roo ◽  
Jolien Debehets ◽  
Marilyne Sousa ◽  
Luman Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Low Pressure ◽  
Liquid Injection ◽  
Pressure Chemical ◽  
Direct Liquid Injection
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